The Chemex is an iconic coffee brewer and is beloved by hundreds of thousands of people around the world. The Chemex has been around since 1941 and was invented by a chemist by the name of Dr. Peter Schlumbohm.
The Chemex in it's truest form is an hourglass shaped uni-body design made of borosilicate glass with a spout formed into it. When I say it's a uni-body design, I mean that it's one piece that you brew into and serve out of, it's your brewer and your decanter. Originally they were all hand blown designs (which can still be purchased) but a large amount of the brewers you see around now are moulded glass designs.
The Chemex can come in a range of sizes and designs. It comes in four brewing sizes; three, six, eight and ten cup options. The most classic design you will see is the hourglass shape with a wooden collar and rawhide tie. The alternative design you will often see is still the hourglass design but with a glass handle rather than the wooden collar. The difference between the two is purely aesthetic. Many people choose to use a Chemex for it's large serving sizes as well as the smooth taste and clarity it provides in your brewed coffee. With Chemex filters being thicker than most, it tends to reduce the amount of natural oils that make it into the cup. The Chemex does not require as finicky of a brewing technique that other brewers might, it allows you to be a little more flexible with how you make your coffee.
Let's get into a basic recipe for how to brew on a Chemex. I often brew on an 8 cup Chemex so that is what I will be using as an example. This recipe will brew enough to make ~20oz of coffee which is enough to fill two mugs. Let's get into it.
- The ratio we will be using is a 1:16 ratio for this brew
- 40g coffee : 640g water
- Grind your coffee to be a medium-course grind (I often use a setting of 24 on the Baratza Encore).
- Place your filter in your Chemex by opening it up to look like a cone shape. One side should have three layers of paper. The three layer side should go over top of the spout to allow for ample airflow while your coffee is brewing.
- Start by pre-wetting your filter with your freshly boiled water. Rinsing the filter thoroughly will eliminate any residual paper taste from seeping into your coffee. Discard your rinse water while holding onto your filter so it doesn't fall out.
- Add your 40g of ground coffee into the filter. Give it a bit of a shake to level the bed of coffee.
- Now it's time to bloom. Pour double the weight of water to coffee. In this case we will be blooming with 80g of water. Add your 80g of water by pouring in a circular motion evenly covering the bed of coffee.
- Give it a gentle stir with a spoon to be sure that all the grounds are saturated with water and are blooming evenly.
- Allow the coffee to bloom for about 45 seconds.
- You can now start pouring to reach your final weight of coffee. Pour in a slow but steady stream, again in circular motions working your way from the middle of the slurry to closer to the edge.
- It's not recommended to allow the coffee to get more than 1cm to the top of the Chemex while brewing. If you find you're getting too close to the top, you can allow the Chemex to drain a bit and then you can continue pouring.
- Once you reach your desired water weight of 640g you can stop pouring.
- Give the coffee slurry a gentle stir with a spoon to loosen up any grounds that may be stuck on the top of the surface.
- Allow your Chemex to drain.
- Your total drain time for this recipe should be between 4:30 and 5:00.
- Once your coffee has come to a slow drip, you may remove and discard the filter and grounds.
- With this recipe your brewed coffee should reach the "button" on the side of the Chemex.
- You can now serve up your coffee.